Graduated receptacle for syringes



Dec. 16, 1947. J, H, BARACH 2,432,605

GRADUATED RECEPTACLE FOR SYRINGES Filed March 1, 1944 |1||l| Ill illlllllll |ll lllllll WITNESSES: INVENTOR J0 5 0A fifiarac/z ATTORNEYPatented Dec. 16, 1947 UNITED STATES PATENT OFFICE GRADUATED RECEPTACLEFOR SYRINGES Joseph H. Barach, Pittsburgh, Pa.

Application March 1, 1944, Serial No. 524,588

2 Claims.

My invention relates to syringes, and has special relation to hypodermicsyringes for administering of medicinal liquids, such as are suitablefor subcutaneous or intravenous injections and for the introduction ofmedicinal fluids into body cavities.

For many 'afllictions of mankind, the amount of medicinal liquid to beadministered subcutaneously or intravenously to a patient must be of anexact volume for a given concentration of the medicine. This isparticularly important in the administering of insulin.

Insulin is at present available in four concentra'tions designated asU-10, U-20, U-40, U-80 and a fifth concentration U-100 may be used. Thehigher concentrations are multiples of the lower concentrations. Thus,insulin designated as U has twice the concentration of U-lO, insulinU-40 has twice the concentration of U-ZO, and U-80 has twice theconcentration of U-iO. The insulin dosage is commonly prescribed interms of a number of units of a certain concentration. If theconcentration prescribed is not available, the patient may use one ofthe other concentrations but the quantity should be divided ormultiplied by a factor corresponding to the concentration used.

"In accordance with the teachings of the prior art a graduated syringeis used for administering the insulin. The syringe is graduated tocorrespond to one .or the other of the concentrations. If the personadministering insulin has a syringe corresponding to one concentrationand only insulin of another concentration is at hand, he should carryoutthe necessary-calculations to determine the quantity of insulin to beapplied. I have found that although a relatively simple computationisinvolved, mistakes are often made in practice by patients and sometimeseven nurses, and an improper quantity of insulin .is given. The personadministering the insulin misinterprets the significance of theidentifications and multiplies .by a factor rather than divides or viceversa. Too little or too much insulin is thus administered and thepatient is injured or endangered.

Syringes, for the purposes above generally specified, now in universaluse are, without .exception, made of glass. In the making of the tubularpart, or cylindrical portion, or tube, of the-syringathe part is blowninto shape. In this process thoughthemanufacturer may exercise thegreatest of care and employ the highest type of craftsmen. the internaldiameter of the tube can 2 not be maintained uniform over its internalaxial length.

In calibrating the syringe, great care must be exercised with each tube.It is thus apparent that large scale, or mass, production is notpossible. Furthermore, the manufacturing cost per syringe is high. Thisdifiiculty is by no means obviated if the internal diameter is cut to agiven dimension. Since the wall thickness of the tube is not uniformenough glass has to be cut away to produce the uniform dimension. Thetubes thus vary in strength. There are thus many rejects. Besides thecost of cutting the glass tubes is by no means a simple and inexpensiveprocess.

Over and in addition to this high cost per syringe is the deplorablefact that glass, for articles of this character, is extremely fragile.The useful life per syringe is thus low.

It is an object of my invention to provide a vessel for administeringdosages of medicaments, the use of which shall involve substantially nopossibi 1ity of error.

Another object of my invention is to provide a vessel for administeringdosages of insulin, in the use of which no computation shall berequired.

A more general object of my invention is to provide a receptacle ofsimple structure for the administration of various substances in varyingdoses.

An ancillary object of my invention is to provide a syringe of novelstructure.

More specifically stated, it is an object of my invention to provide asyringe for administering dosages of a liquid that is available in aplurality of concentrations without the necessity of computing thequantity of any available concentration that is to be used.

The novel features that I consider characteristic of my invention areset forth with particularity in the appended claims. The invention,itself, however, both as to its organization and its method ofoperation, together with additional objects and advantages thereof willbest be understood from the following description of specificembodiments when read in connection with the accompanying drawing, inwhich:

Figure l is a View in longitudinal section except for portions of thepiston, or plunger, showing a preferred embodiment of my invention;

Fig. 2 is a view in perspective showing two surfaces of the block usedin the practice of my invention;

Fig. 3 is a view in perspective showing the remaining two surfaces ofthe block;

Fig. 4 is a diagrammatic view showing a development of the block; and

Fig. is an enlarged view showing a detail of the end structure of thepiston or plunger.

The syringe shown in Fig. 1 comprises a cylindrical barrel l composed ofa transparent plastic 39. My experiments have shown that the plasticsknown as thermoplastic methyl methacrylate resin and polystyrene alsohave merit. Some discussion of these will be made hereinafter.

This barrel I is prov ded at one end with a. nozzle 2 and a hypodermicneedle attachment 3 shrunk-fit on the end of the resin. The attachmentmay be of stainless steel or any other alloy and may be attached bymeans other than a shrunk-fit as for instance threads or cement, orboth, This attachment is provided with a shoulder 4 against which theremovable graduated rectangular ferrule or sheath 5 abuts. Theattachment may be provided with threads, as shown at 6, for receivingconventional syringe elements as nozzles or needles.

The barrel I, as already stated, is transparent. In the preferredembodiment the plunger '3 is made of tinted plastic of the same type asthe barrel. A dark blue color is the preferred color, but any othercolor as red or green may be used. The color chosen should contrast withthe color of the medicine to be administered. If the medicine is a clearliquid, which is usually the case, the choice of color for the pistonmay suit the taste of the user.

At the other end of the barrel, I provide another reinforcing metallicend or attachment 8. This attachment may be threaded as shown at 9. Aknurled sleeve nut ill shaped as shown is screwed against the ferrule 5to hold it firmly against stop 4. The ferrule may be provided with anotch l I to hold the ferrule in a given desired relation to theattachment 3.

To the left of sleeve nut I0, I position the member l2. This member [2may be annular or oval shaped or generally rectangular so as to providean abutment for the index finger and middle finger of the user when thesyringe, in use. is held between these two fingers while the thumb isositioned on the knob It.

The syringe is thus disposed in a hollow block, sheath, or ferrule, 5composed of metal or composition material, such as a phenoliccondensation product. The sheath 5 has an opening at one end to receivethe syringe. It is of substantially the same length as the tube orbarrel I and when the syringe barrel is inserted in the open end, thenut Ill, when in place, rests against the left-hand end of the sheath orblock. The cross section of the block 5 is preferably a square.

Graduations l4, l5, I6 and I! are provided on the four surfaces I8, I9,20 and 2!, respectively, of the block 5 to correspond to the fourconcentrations of insulin. The spacings between the graduations and thelabeling on any surface corresponds to the concentration associated withthe surface and the surface is clearly labeled to indicate whatconcentrations it represents.

The zero marks of the graduations lie in the plane of the inner endsurface of the base of the syringe tube 22 when it is disposed in'theblock. The distance between the zero mark and any other mark of agraduation, therefore, corresponds to the quantity of a liquid withinthe tube, the level of which is in the plane of the upper graduation.

The surfaces of the sheath are provided with slots or windows, as 23,extending along the whole length of the graduations so that the level ofthe liquid within the syringe tube may be compared with the graduations.To facilitate the comparison, the edges, as 24 and 25, of the slots 23adjacent the barrel l are beveled so that their cross-section is sharpand the graduations extend to the extreme edges of the bevels.

Where the piston or plunger, as 26, is to fit into an accuratelymachined cylinder openingZl and the piston has an outside diameter thatis less than the inside diameter only by from one twothousandth to onetwenty-five thousandth of an inch, considerable difficulty may beexperienced in assembling the piston and cylinder.

To facilitate the insertion of the piston in the cylinder, I provide thepiston end to be inserted in the cylinder with a small groove 28 spaceda short distance from the end of the piston. To provide this groove, thepiston is provided with a small shallow V-shaped, orsemicircular-shaped, circumferential cut at the end. Between thisgroove, or cut, and the end of the piston, I provide a small ridge, orland 29 having exactly the same outside diameter as that of the outsidediameter of the piston. This land may have a width in the axialdirection of from one sixtyfourth to one sixteenth of an inch, dependingsomewhat on the diameter of the piston.

The groove on the other hand may have a width in the axial directionmeasured in the surface of the plunger of from one-thirty-second tothreethirty-seconds of an inch. The referred width of the land isone-thirty-second of an inch and the preferred width of the groove isone-sixteenth of an inch. These preferred dimensions work mostsatisfactorily for all sizes of syringe plungers except the very smallsyringes.

That the diameter of the piston in the plane of the land he the same asthat of the main body of the piston itself is important, otherwise thebenefits of this detail of my invention are not fully realized. Thiswill become more apparent from a study of Fig. 5. The groove permits theinsertion of the piston within the cylinder at least in one region-thelower region as shown in Fig. 5--for a distance substantially thedistance of the bottom of the groove from the end of the piston.

As the piston is thus moved in, the axes of the cylinder and piston areautomatically brought into such a relation that they intersect at somepoint as 30. The first step in the proper positioning of the pistonwithin the cylinder is thus easily and substantially automaticallyobtained regardless of the fact that in moving the left-hand end of thepiston, the piston axis may swing to any position of a small solid anglehaving its origin at 30 in the axis of the cylinder. Actually but littleskill is required to bring the axes 3i and 32 into alignment. The resultis that a very accurately fitting piston may be inserted into a cylinderin from one seventh to one tenth the time required for a similar pistonnot provided with the land and groove.

The end of the piston may also be cut so that the end is very slightlyconcave as shown at 33. This provides for a better liquid seal. But itmust be remembered that the showing is very exaggerated. The cut isactually such that on any axial section, the angle BAC is very slightlyless than ninety degrees. The angle is so chosen that for normalpressures exerted at the outer end of the piston, 'when the inner endcontacts the bottom of the cylinder, the angle BAC will become a rightangle because of the slight resil- 5 iency of the material thus forcingevery bit of liquid out of the cylinder.

These refinements provided by the groove and land and the cut at the endof the piston are usually not necessary, nor is it necessary for mostpurposes to attain an accuracy of both piston and cylinder to within onetwenty-five thousandth of an inch. I am merely providing theserefinements to make my syringe a highly precise instrument as well.

Although I have shown and described a certain specific embodiment of myinvention, I am fully aware that many modifications are also possible.My invention, therefore, is not to be restricted except insofar as isnecessitated by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. For use with a syringe for applying dosages of a liquid which existsin a plurality of concentrations, a block having a plurality of facescorresponding in number to said concentrations and an opening to receivesaid syringe, said faces being graduated to correspond to saidconcentrations and having slots therein so that the column of saidliquid and thus the volume thereof in said syringe may be compared withthe graduations, the graduations on said faces being such as 6 toindicate the volume that a liquid, of concentration corresponding to anyface, should have for a dosage of a given value.

2. For use with a syringe for applying dosages of insulin or any otherinjectable fluid which exists in one or more concentrations, a blockhaving a quadrilateral cross-section and an opening to receive saidsyringe, the faces of said block beihg graduated to correspond tovarious concentrations and having slots therein so that the level ofsaid fluid in said syringe may be compared with the graduations, thegraduations on said faces being such as to indicate the level that thefluid within the syringe, of concentration corresponding to any face,should have for a dosage of a given value.

JOSEPH H. BARACH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 765,611 Carr July 19, 19041,832,436 Wagenseller Nov. 17, 1931 1,471,644 Bandman Oct. 23, 1923

